<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script src="../../js/jquery-3.4.1.js"></script>
    <script>
        $(document).ready(function () {

            var originalObject = {};
            $.each($('#beneficiaryForm').serializeArray(), function(i, kv) {
                originalObject[kv.name] = kv.value;

            });
            console.log("originalObject",originalObject);

            var serializedata = $("#beneficiaryForm").serialize()
            console.log("serializedata",originalObject);
        }) ;

    </script>
</head>
<body>
    <form id="beneficiaryForm">
        First name <input name="a" value="a1"/>
        First name<input name="b" value="b1"/>
        <input type="button"  value="提交"/>
    </form>
</body>
</html>